Table 1.

Main techniques for the measurement of endothelial function.

Technique	Site	PROS	CONS
Venous occlusion plethysmography	Venous system of limbs	Non-invasive Accuracy	Strict protocol to follow
Flow-mediated dilation	Forearm	Non-invasive High reproducibility Correlation with invasive measurements	Operator skill required Strict protocol to follow
Ankle–brachial index	Lower limb	Non-invasive Easily and quickly obtainable Cost-effective	Indirect measure of ED
Peripheral arterial tonometry	Microvasculature of fingertips	Non-invasive Operator independent Easy to use	Strict protocol to follow Costly probes
Thrombolysis in myocardial infarction (TIMI) frame count and TIMI myocardial perfusion grades	Coronary Microvacular disease	Accuracy Relatively easy	Invasive No information about ED underlying mechanisms
Coronary flow reserve	Coronary Microvacular disease	Feasible Safe Reproducible	Invasive Requires hyperaemia Operator-dependent